Search Results (295)

Agro-industrial wastewater, rich in nutrients and organic matter, represents both an environmental challenge and a valuable resource for biomass valorization. This study assessed the formation, functional performance, and compositional quality of microalgal–bacterial aggregates (MBAs) cultivated exclusively in agro-industrial wastewater under different hydrodynamic conditions. Open photobioreactors operated at 50 and 100 rpm were used to promote aggregate development, followed by closed static and dynamic batch operations to evaluate contaminant removal efficiency. The systems achieved high pollutant removal rates, including 98% ammonium, 95% phosphate, 65–80% Chemical Oxygen Demand (COD), and complete elimination of E. coli, while moderate agitation enhanced aggregation and settleability without compromising treatment efficiency. Dynamic operation maintained more stable removal performance and biomass retention compared to static systems. The recovered biomass exhibited a favorable nutritional profile (12.5% protein, 4.39% lipids, and 31% dietary fiber) and tested negative for cyanotoxins and pathogens, confirming its microbiological safety. Overall, the findings demonstrate that MBAs cultivated from agro-industrial wastewater can effectively couple bioremediation with the production of safe, nutrient-rich biomass, offering a sustainable and circular solution for wastewater management and bioresource recovery. Full article

Sugarcane (Saccharum officinarum L.) is one of the world’s most important agro-industrial crops, and the technological quality of its juice directly determines the efficiency of sucrose extraction and recovery processes. In tropical soils with low P availability, conventional fertilization is often inefficient due to nutrient immobilization, which increases production costs and environmental risks. In this regard, plant growth-promoting bacteria (PGPBs) have emerged as a sustainable alternative to improve nutrient use efficiency. This study evaluated the effect of inoculation with A. brasilense, P. fluorescens, and B. subtilis (single strains and consortia), combined with two levels of residual p (160 and 225 kg P₂O₅·ha⁻¹), on the technological quality of the juice and the microbial dynamics of the rhizosphere. The experiment was conducted under tropical field conditions using a randomized complete block design with split plots and five replications. A highly significant interaction between phosphorus and inoculation (p < 0.001) was observed for °Brix, Pol, purity, and sucrose. The B. subtilis + P. fluorescens consortium under reduced phosphorus (160 kg P₂O₅·ha⁻¹) achieved the highest values for sucrose (17.26%), °Brix (20.32), and purity (87.03%). A linear regression model showed that rhizosphere microbial density explained a large proportion of the variability in sucrose (R² = 0.96; β = 2.02; p < 0.001). Principal component analysis explained 91.8% of the total variance, clearly separating the consortia from the individual strains and the controls. These results indicate that PGPB consortia, combined with moderate pH fertilization, can improve the technological quality of sugarcane while enhancing rhizosphere functionality, representing a promising strategy for more sustainable production systems in tropical environments. Full article

Microplastic pollution has become a significant environmental concern due to its persistence and widespread impact across ecosystems. These plastic particles (1 μm to 5 mm), originating from larger plastic debris or industrial sources, accumulate in diverse habitats, affecting biodiversity and human health. Microplastics resist natural degradation, posing challenges to both ecological sustainability and waste management strategies. Although numerous studies have explored microbial degradation, most existing research focuses primarily on bacteria, leaving the role of filamentous fungi comparatively underexplored. This represents a significant research gap, because fungi secrete a variety of extracellular enzymes, including laccases, peroxidases, and esterases, which play crucial roles in the breakdown of synthetic polymers. These enzymes facilitate the depolymerization of microplastics by targeting polymer chains and increasing their susceptibility to further microbial degradation. However, the underlying enzymatic mechanisms and their effectiveness in microplastic remediation remain insufficiently characterized. Here, we critically review the potential of filamentous fungi for microplastic biodegradation, emphasizing their oxidative and hydrolytic enzyme systems, biosurfactant production, and mechanisms of adsorption and mineralization. The novelty of this review lies in consolidating the most recent mechanistic insights into fungal-driven depolymerization pathways, integrating them with advances in genetic engineering, bioprocess scale-up, and regulatory perspectives, areas rarely combined in previous reviews. We identify current limitations related to environmental applicability, enzyme accessibility, and the lack of standardized protocols, and propose strategies to overcome these challenges through enzyme immobilization, microbial consortia design, and synthetic biology approaches. By addressing these gaps, filamentous fungi may contribute to the development of sustainable strategies for plastic pollution mitigation and support circular economy approaches toward polymer biodegradation. Full article

Microbial communities regulate the transformation and stabilization of nutrients during composting; however, current knowledge on their specific functional roles across composting stages remains poorly integrated. This review examines the pivotal role of microbial mediation in nitrogen (N) and phosphorus (P) dynamics during composting and their subsequent impact on soil health. We analyze how biotechnological interventions—specifically the inoculation of functional microbial consortia (phosphate-solubilizing bacteria, phosphate-accumulating bacteria, and nitrifiers) and the application of physicochemical additives such as biochar—reconfigure microbial succession patterns to mitigate gaseous losses and enhance nutrient bioavailability. Several studies have reported substantial reductions in ammonia (NH₃) and nitrous oxide (N₂O) emissions under specific composting conditions, while simultaneously promoting the stabilization of labile P into more recalcitrant forms, including polyphosphates. Furthermore, the application of mature compost to agricultural systems induces a profound ecological reassembly of the soil microbiome, shifting community composition toward copiotrophic dominance (Pseudomonadota and Bacteroidota) and increasing functional redundancy. These microbial and functional shifts enhance soil resilience to environmental stressors—such as drought and temperature fluctuations—by stabilizing extracellular enzyme activity and reinforcing microbial co-occurrence networks. We conclude that managing microbial interactions along the compost–soil continuum is essential for developing organic amendments optimized for specific soil and crop requirements. This integrated approach represents a cornerstone of precision sustainable agriculture and contributes to climate change mitigation through soil health restoration. Full article

Cannabis sativa L. is a multipurpose crop of increasing agricultural and medical relevance, whose productivity and phytocannabinoid profile are influenced not only by genotype and environmental factors but also by the composition of its microbiota. This review synthesizes current knowledge (2020–2026) on the rhizosphere and endophytic microbiota of hemp, with particular emphasis on plant growth-promoting bacteria (PGPB) and their mechanisms of action. Molecular studies indicate that hemp-associated bacterial communities are dominated by Proteobacteria, Actinobacteriota, Firmicutes and Bacteroidota, with genotype-, tissue- and developmental-stage-dependent variation. PGPB influence plant performance through direct mechanisms, including biological nitrogen fixation, phosphate solubilization, siderophore production and phytohormone synthesis (indole-3-acetic acid (IAA), gibberellins, cytokinins, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase), as well as indirect mechanisms such as antibiosis, enzyme-mediated pathogen inhibition and induction of systemic tolerance to abiotic stress. Experimental studies demonstrate that inoculation with selected strains or consortia can enhance biomass accumulation, improve germination and root architecture, increase resistance to Fusarium oxysporum and modulate cannabinoid and terpene profiles. Importantly, plant responses are cultivar-specific, highlighting the need for genotype-tailored microbial formulations. Full article

The use of sewage sludge for the bioremediation of hydrocarbon-contaminated soils remains insufficiently documented, particularly regarding microbial dynamics and material behavior during treatment. Although petroleum-hydrocarbon contamination severely disrupts soil functions, sewage sludge—through its high organic matter content, active bacterial communities, and fine mineral fraction—offers potential for the sustainable remediation of such soils. Three soil–sludge mixtures (P1:N1, P2:N1, P1:N2) were monitored to assess hydrocarbon degradation, bacterial community dynamics, and material behavior. Hydrocarbon-degrading and hydrocarbon-tolerant bacteria remained active, while sludge-derived Enterobacteriaceae declined below detection limits. Enrichment cultures of the sludge yielded three hydrocarbon-degrading strains (Providencia alcalifaciens IBBN1, Klebsiella pneumoniae IBBN2, Acinetobacter tandoii IBBN3), highlighting the metabolic potential of the active microbial communities. A moderate increase in surfactant concentrations reflected both residual anionic surfactants and biosurfactant production by these consortia, facilitating hydrocarbon mobilization. Total petroleum hydrocarbons (TPH) decreased by 45–60% (IR), and GC-FID analysis showed preferential degradation of C10–C40 fractions. Heavy-metal concentrations remained stable, indicating no geochemical changes or inhibitory effects on bacterial activity. Overall, the results confirm the potential of sewage sludge as a sustainable amendment that accelerates hydrocarbon biodegradation and supports integrated soil-restoration strategies. Full article

Lignocellulose is degraded in the rumen by diverse microorganisms. This study aimed to select the top ruminal microbes associated with an anaerobic fungus (AF) capable of forming consortia that facilitate biogas production from wheat straw. The workflow included the following steps: (1) batch reactors, divided into three compartments with porous membrane bags containing wheat straw, were assembled. The outermost compartment was inoculated with freshly collected rumen content. The first microbes colonizing the wheat straw in the innermost compartment within 72 h were identified. (2) Synthetic consortia were assembled comprising the following identified microbes: an anaerobic fungus (AF) (Neocallimastix lanati); methanogenic archaea (M) (Methanobrevibacter ruminantium or Methanobrevibacter gottschalkii); bacteria (B) (Butyrivibrio hungatei or Succinoclasticum ruminis). (3) Wheat straw was subjected to 7-day pretreatments with these synthetic consortia. (4) The pretreated straw served as substrate in biochemical methane potential (BMP) tests that used a biogas reactor digestate as the inoculum. The pretreated straw produced elevated biomethane yields; nonetheless, this process needs further optimization. The cross-kingdom AF + M + B consortia increased methane production by 35–70%, and superior volatile fatty acid production was confirmed via HPLC. The results suggest novel strategies for advanced practical biogas/biomethane technologies. Full article

Algae rarely occur as solitary phototrophs in nature or engineering; instead, they are embedded in complex bacterial consortia that control their physiology, productivity and ecological performance. The phycosphere, a microscale niche rich in algal exudates, promotes extensive metabolic exchange and chemical signaling, defining these associations. Bacteria capitalize on the dissolved organic carbon released by algae, providing growth supporting molecules such as vitamins, trace metals, and siderophores, as well as regenerated inorganic nutrients. Bidirectional beneficial interactions range from obligate mutualism to facultative commensalism and antagonism, depending on environmental context and community membership. Bacterial partners can stimulate algal growth, morphogenesis, and stress tolerance, as well as modulating defense and programmed cell death during the decline and bloom succession of algae resulting from algicidal taxa. Metabolic cooperation, QS signaling, extracellular enzyme activity, and chemically induced gene expression produce the exometabolome in the phycosphere, which in turn reprograms gene expression in all partners. Recent advances in multi-omics toolboxes, single-cell isotopic analyses, and microfluidics have greatly enhanced our understanding of the functional and spatiotemporal orientation of algal microbiomes. Ecologically, algal–bacterial interactions manage the phytoplankton community structure, control HABs, and modulate carbon and nutrient fluxes in both marine and freshwater realms. Biotechnologically, engineered algal–bacterial consortia are a promising tool for enhancing biomass production, stabilizing large-scale cultivation, improving wastewater treatment, and upgrading biofuels and fine chemicals. Despite these notable research advances, the context- and species-dependent complexity of multispecies interactions remains a major obstacle to their practical modeling and scalable implementation. Integrative research frameworks that combine molecular, ecological, and bioengineering approaches are urgently needed to unlock the full potential of sustainable applications in the future. Full article

The use of microbial consortia has emerged as a promising strategy to improve crop performance under abiotic stress, although their effectiveness under field conditions remains variable. Here, we evaluated whether plant growth-promoting (PGP) bacterial consortia assembled based on synergistic PGP traits can improve physiological performance, yield, and grain quality of yellow lupine (Lupinus luteus L.) under field-based drought conditions. A semi-controlled, field-based pot experiment was conducted under contrasting water regimes (irrigated and drought) to evaluate four rhizobacterial strains (Microbacterium sp. S13.2, Variovorax sp. S14.7, Bacillus sp. S31, and Lysinibacillus sp. S34), assembled into four consortia: two characterized by high (C1 and C2) and two by low (C3 and C4) auxin production and ACC deaminase activity, along with an uninoculated control. Physiological responses were monitored across phenological stages through stomatal conductance and photosynthetic pigments, while agronomic traits, yield components, and grain quality were assessed at harvest. Inoculation effects were stage-dependent and became more evident under drought conditions. Consortia C1(Microbacterium sp. S13.2 + Variovorax sp. S14.7) and C2 (Bacillus sp. S31 + Lysinibacillus sp. S34) consistently improved biomass accumulation, seed number, and grain yield compared to the uninoculated control, whereas C3 (Lysinibacillus sp. S34 + Variovorax sp. S14.7) and C4 (Bacillus sp. S31 + Variovorax sp. S14.7) showed limited or neutral effects. Multivariate analysis indicated distinct performance strategies, with C1 associated with higher productivity and C2 with improved yield stability under drought. Grain quality parameters remained stable across treatments. These results show that cooperative microbial consortia can improve lupine performance under water-limited conditions, and their effectiveness depends on the functional interactions among consortium members. Full article

Background/Objectives: Freshwater microalgae–bacteria consortia are increasingly utilized in wastewater treatment and biomass production. However, bacteria associated with the algal phycosphere may act as environmental reservoirs of multidrug-resistant (MDR) phenotypes and antibiotic resistance genes (ARGs), including resistance to last-resort antibiotics such as colistin. Methods: An axenic culture of the freshwater microalga Pectinodesmus pectinatus was established using a NaClO-based cleaning protocol. Three phycosphere-associated bacterial strains (Chryseobacterium sp., Pseudomonas monteilii, and Stenotrophomonas pavanii) were isolated and identified by 16S rRNA gene analysis. Antimicrobial susceptibility testing was performed using broth microdilution against 16 antibiotics. Whole-genome sequencing of the most resistant isolate, S. pavanii, was conducted using Oxford Nanopore technology, followed by genome annotation and in silico resistome analysis using CARD, AMRFinderPlus, and ResFinder. Results: Among the three isolates, S. pavanii exhibited the broadest resistance profile, including high minimum inhibitory concentrations (MICs) to multiple β-lactams and colistin (MIC ≥ 16 μg/mL). No plasmid-borne mcr genes were detected. Instead, the genome encoded multiple chromosomal determinants potentially associated with polymyxin non-susceptibility, including lipid A and lipopolysaccharide modification pathways (e.g., arn genes and eptA), outer-membrane maintenance and LPS transport systems, multidrug efflux pumps, and regulatory elements. Integration of genomic and phenotypic data suggested that the observed colistin non-susceptibility may be associated with intrinsic chromosomal determinants inferred from whole-genome analysis. Conclusions: This study demonstrates that the P. pectinatus phycosphere can harbor multidrug-resistant (MDR) bacteria, including strains exhibiting colistin non-susceptibility potentially associated with a repertoire of intrinsic chromosomal resistance mechanisms inferred from genomic analysis. Therefore, freshwater microalgae-based systems should be considered potential environmental reservoirs contributing to the dissemination of antimicrobial resistance. Full article

Peanut (Arachis hypogaea L.) forms root nodules that host microbial communities influencing plant nutrition and stress tolerance, and herbicide use may act as an environmental filter altering the cultivable nodule microbiota. This study isolated and characterized bacteria from peanut nodules collected in fields with and without imazapic application in Jaboticabal, São Paulo, Brazil. Eight isolates were obtained, and one hemolytic strain was excluded after pathogenicity screening. Based on 16S rRNA gene sequencing and phylogenetic analysis, the isolates were identified as Bacillus aerophilus, Bacillus inaquosorum, Bacillus subtilis, Bradyrhizobium yuanmingense, Burkholderia lata, and Rhizobium tropici. Nodules from herbicide-treated plants yielded exclusively Bacillus spp., whereas those from non-treated plants showed greater taxonomic diversity. Molecular screening detected genes associated with biological nitrogen fixation (nifH) and nodulation (nodA, nodB, nodC, nodD), indicating potential functional capacity. In greenhouse assays, the isolates showed strain-dependent effects on early plant development, with pronounced responses in root growth and nodulation. Burkholderia lata and bacterial consortia enhanced root development and nodulation, with performance comparable to the commercial inoculant SEMIA 6144. Herbicide management shapes the cultivable nodule microbiota, and selected isolates show potential as bioinoculants for peanut production systems. Full article

Fermented dairy products with probiotic and functional properties are a promising matrix for modulation of the human microbiome. The functionality of such products will depend not only on the technological properties of the lactic acid bacteria included in the starter culture but also on the combined effects of metabolites, enzymatic activity, stress tolerance, and strain-specific adaptation mechanisms. The aim of this work was to conduct a comprehensive analysis of Lactobacillus strains to facilitate the design of microbial consortia for the development of fermented products with diverse functional properties. Twenty Lactobacillus strains from different species were investigated using microbiological, physicochemical, and biochemical methods to evaluate antagonistic activity against opportunistic microorganisms and to assess changes in amino acid and organic acid profiles, vitamin content, fatty acid composition, and enzymatic activity. Additionally, proteomic analysis was performed to create a matrix of functional complementarity of the studied strains, representing proteins associated with antimicrobial activity, bacteriocin transport, resistance to oxidative stress, surface structure formation, and adhesion. It was shown that the studied strains exhibit pronounced functional heterogeneity, demonstrating the feasibility of scientifically based selection of strains to create next-generation fermented dairy products with predictable properties. Full article

Background: Subclinical psychological symptoms—such as low mood, perceived stress, and poor sleep—affect a large portion of the population and can impair quality of life despite remaining below clinical thresholds. The gut–brain axis has emerged as a promising target for interventions that support emotional and psychological resilience. Probiotics and postbiotics are gaining attention for their potential to modulate mood and stress via microbiome-related mechanisms, but human evidence remains limited, particularly in non-clinical populations. Objectives: We aimed to assess the effects of a two-strain combination of live microorganisms alongside a two-strain combination of heat-treated inactivated microorganisms on outcomes associated with anxiety, mood, perceived stress, and quality of life in healthy adults experiencing mild stress. Methods: This study was conducted in two parts. In Part I, a randomized, double-blind, placebo-controlled study, 100 participants were randomized to receive either a blend of live microorganisms (Bifidobacterium longum CECT 7347 and Lactobacillus rhamnosus CECT 8361) or an identical placebo once daily for 12 weeks. In Part II, a pilot feasibility study, a subset of eight placebo non-responders from Part I received the heat-inactivated preparation of the same bacterial strains in a 6-week trial extension phase. For Parts I and II, the primary outcome was the change in the Hamilton Anxiety Rating Scale (HAM-A). Secondary outcomes included measures of mood (Beck Depression Inventory (BDI); Patient Health Questionnaire-9 (PHQ-9)), stress (state and trait anxiety inventory (STAI); Perceived Stress Scale (PSS)), sleep (Pittsburgh Sleep Quality Index (PSQI)), quality of life (36-item Short Form Survey (SF-36)), gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale (GSRS)), salivary cortisol and microbiome modulation. Results: In Part I, there were no significant effects of the live blend on the HAM-A, indicating that the primary endpoint was not met. In addition, no significant effects were seen on the STAI or PSS scores when compared to the placebo. However, participants consuming the live blend trended toward a reduction in total PHQ-9 scores compared to placebo (p = 0.089), whilst preliminary exploratory analyses suggested an improvement in anhedonia (p = 0.045). Furthermore, there was a significant improvement in the vitality domain of the SF-36 compared to placebo (p = 0.017). On microbiome analysis, it was noted that consumption of the live blend was linked to the preservation of butyrate-producing bacteria, particularly members of the Pseudoflavonifractor genus and the Clostridium SGB6179 species. Furthermore, the abundance of B. longum species was found to be inversely associated with the total PSS Scores. In Part II, supplementation with the inactivated preparation resulted in significant within-group improvements for the vitality (p = 0.006) and social functioning (p = 0.010) domains of the SF-36 and improvements in PSS scores compared to baseline (p = 0.050). Conclusions: Supplementation with either the dual-strain live or inactivated formulations was associated with significant improvements in the vitality domain of the SF-36, whilst participants receiving the inactivated formulation demonstrated lower perceived stress and improved social functioning compared to baseline. Overall, the findings from this pilot study suggest that these two biotic consortia are well-tolerated and may be associated with improvements in measures of vitality in individuals with subclinical psychological symptoms. The subtle observations detected for stress and anhedonia suggest that further well-powered trials are needed to better characterize these findings, potentially in populations with greater baseline symptomatology. Full article

This study provides novel insights into the gradual development of an algal-bacterial self-flocculent biomass in a 400 L pilot-scale raceway pond for wastewater treatment to enhance sustainability and minimize environmental footprint. The synergetic interaction of algal-bacteria consortia improves nutrient removal while enabling biomass concentration increase. Initially, the microalgae-bacteria biomass was gradually developed by increasing the operating volume from 60 to 400 L. After 80 days, the biomass reached a plateau at a concentration of about 4 g L⁻¹, and exhibited excellent settling characteristics. The initial settling velocity was 14.8 cm min⁻¹ and a settling time of 3 min was required to achieve efficient separation. The reactor achieved high treatment efficiency of about 95% for all nutrients (organic matter, nitrogen and phosphorous) after the 80th day. The kinetic analysis showed that nutrient removal followed first-order kinetics, with soluble chemical oxygen demand and ammonia removal reaching 0.017 and 0.020 h⁻¹, respectively. The results demonstrate high pollutant removal efficiencies and design guidelines for the use of increased concentrations of microalgae–bacteria consortia in urban wastewater treatment practice, an alternative green way for solving present-day wastewater treatment problems. Full article

Chickpea flour represents a valuable plant-based ingredient due to its high protein and fiber content; however, its application is limited by antinutritional factors and off-flavor compounds. Fermentation with LAB and yeasts, applied individually or in consortia, resulted in significant microbiological, nutritional, and aromatic changes. The fastest acidification (pH 3.9) and the most effective control of Enterobacteriaceae (<4 log CFU/g after 48 h) were observed in samples containing Lactiplantibacillus plantarum LP23, both as a monoculture and in combination with Debaryomyces hansenii Y15A. Peptide content significantly increased in all fermented samples compared to the control, with a synergistic effect in the co-culture Yarrowia lipolytica Y3 + Lacticaseibacillus paracasei L (around 230%). A pronounced reduction in raffinose-family oligosaccharides was observed, especially in the consortia Y. lipolytica Y3 + Lcb. paracasei L and D. hansenii Y15A + Lacp. plantarum LP23 (0.11–0.16 mmol/100 g). Samples with lower total volatile levels showed higher olfactory acceptability due to a marked reduction in aldehydes (up to 70–95% vs. control), and a balanced accumulation of alcohols, esters, ketones, and organic acids. Overall, LAB–yeast consortia effectively enhanced the nutritional quality, safety, and sensory properties of chickpea flour, supporting its use as a functional ingredient in plant-based foods. Full article